Dental Prosthesis and Its Manufacturing Method

ABSTRACT

Disclosed herein are a dental prosthesis and its manufacturing method for restoring a lost tooth. The dental prosthesis has a male member formed on a holding part attached on an adjacent tooth for attaching an artificial tooth on the adjacent tooth and a female member formed in the artificial tooth so that the artificial tooth and the adjacent tooth can be connected with each other without grinding the adjacent tooth. The method for manufacturing the dental prosthesis includes the steps of duplicating an original model, waxing up the duplicated model, holding a sprue on the duplicated model in a state where the duplicated model is waxed up, and investing, burning out and casting the duplicating model.

TECHNICAL FIELD

The present invention relates to a dental prosthesis and itsmanufacturing method for restoring lost tooth, and more particularly, toa dental prosthesis which has a male member formed on a holding partattached on an adjacent tooth for attaching an artificial tooth on theadjacent tooth and a female member formed in the artificial tooth sothat the artificial tooth and the adjacent tooth can be connected witheach other without grinding of the adjacent tooth, and a method formanufacturing the dental prosthesis which includes the steps ofduplicating an original model, waxing up the duplicated model, holding asprue on the duplicated model in a state where the duplicated model iswaxed up, and investing, burning out and casting the duplicated model.

BACKGROUND ART

In general, to restore a lost tooth, an adjacent tooth located by theside of an artificial tooth to be restored is ground, and a crown madeof metal or ceramic material is covered on the ground adjacent tooth andconnected and fixed to the artificial tooth.

For a representative example of the conventionally dental prosthesis,there is a crown bridge. In the case of the conventional crown bridge,adjacent teeth 1 located at both sides of an artificial tooth to berestored are ground from the dotted line to the solid line shown in FIG.1, and the artificial tooth 2 shown in FIG. 2 is connected to a crown 2a formed on an abutment and fixed at the ground portion.

However, the conventional crown bridge has several disadvantages in thatit causes degeneration or exposure of dental pulp, or hypersensitivitysince a loss of tooth substance is increased, and in that it isimpossible to restore the original occlusal form due to the grinding ofthe occlusal surface of the adjacent teeth. Moreover, occasionally, itis necessary to previously carry out endodontic treatment since anamount of tooth grinding is increased during restoration of a severelyinclined tooth.

Alternatively, there is an implant as the dental prosthesis. The implantprosthesis is a method for fixing an artificial tooth using a screwafter implanting a metal artificial root. However, the implant hasseveral disadvantages in that it takes much time and money to fix theartificial tooth, has limitations in restoration in the case of patientsof severe periodontal disease, wasting diseases, diabetes andhematologic diseases, and is relatively weak to lateral pressure.

Therefore, development of a dental prosthesis which is easy to operateand can fix the artificial tooth without grinding of adjacent teeth hasbeen required. In the prior art prostheses, it is difficult to applyvarious prostheses according to conditions of adjacent teeth, since itis unavoidable to form holes in the adjacent teeth or grind the adjacentteeth to hold the fixed state of the prostheses.

Meanwhile, a method for manufacturing the conventional dental prosthesisincludes the steps of waxing up an original model of the prosthesis,removing the waxed-up model from the original model, investing andcasting the waxed-up model after holding a sprue on the waxed-up model,and mounting it to the original model.

However, such conventional method has a disadvantage in that it isdifficult to obtain holding force to the maximum.

DISCLOSURE OF INVENTION Technical Solution

Accordingly, it is an object of the present invention to provide adental prosthesis and its manufacturing method, which can fix a holdingpart to an adjacent tooth with no or little grinding of the adjacenttooth, thereby easily and firmly fixing an artificial tooth to theholding part attached on the adjacent tooth and providing natural andvarious outward appearances according to tooth conditions.

To achieve the above object, the present invention provides a dentalprosthesis which has a male member formed on a holding part attached onan adjacent tooth for attaching an artificial tooth on the adjacenttooth and a female member formed in the artificial tooth so that theartificial tooth and the adjacent tooth can be connected with each otherwithout grinding of the adjacent tooth, and a method for manufacturingthe dental prosthesis which includes the steps of duplicating anoriginal model, waxing up the duplicated model, holding a sprue on theduplicated model in a state where the duplicated model is waxed up, andinvesting), burning out and casting the duplicated model.

ADVANTAGEOUS EFFECTS

The present invention which has no anesthesia and grinding of teeth canpromote dental health since a patient can go to a dental clinic in agood feeling without fear to dental care losing no time of restoration,and restore teeth even in the case of patients, who have hypertension orangina pectoris patient or are warned to anesthesia, restricted inrestorations.

The dental prosthesis according to the present invention does not causeover-sensitive reaction and require endodontic treatment after the toothrestoration since it restores the tooth with no grinding of the toothand no influence on the dental pulp, and can prevent decay of teethsince it conserves enamel, which is the hardest in a human body.Furthermore, the dental prosthesis according to the present inventioncan keep the present occlusion state since the occlusal surface is notground, and does not provide the patient with a sense of foreignsubstance since the opposite tooth is not changed and the contact pointwith the opposite tooth is kept as it is. In addition, the dentalprosthesis does not cause a damage of soft tissue, which may be causedduring grinding of the tooth, and prevents decay of teeth by melting ofcement due to improper grinding of the tooth.

Moreover, the dental prosthesis according to the present invention canremarkably reduce medical accidents since there is no cross infectionbetween patients due to improper disinfection in a dental clinic, doesnot need anesthesia agent and tooth grinding agent, remarkably reducesmedical consultation hours, and can be easily removed when the dentalprosthesis has to be unavoidably removed. Therefore, the dentalprosthesis according to the present invention is the mosthuman-friendly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view showing a grinding portion in the case where aconventional dental prosthesis is applied;

FIG. 2 is a side view showing a mounted state of the conventional dentalprosthesis;

FIG. 3 is an exploded perspective view of a dental prosthesis accordingto the present invention;

FIG. 4 is an enlarged view of a lingual side of FIG. 3;

FIG. 5 is an enlarged view of a lingual side of male members formed atboth ends of a holding part of the dental prosthesis according to thepresent invention;

FIG. 6 is a perspective view and a plan view showing a state where anS-shaped holding part is mounted on adjacent teeth according to thepresent invention;

FIG. 7 is a perspective view of an integrated type holding part of thepresent invention;

FIG. 8 is a perspective view of a separated type holding part of thepresent invention;

FIG. 9 is a perspective view showing a coupling part formed at the rearpart of the holding parting FIG. 8;

FIG. 10 is a perspective view showing coverage of the pit, thenon-functional cusp and a portion of the occlusal surface;

FIG. 11 is a perspective view of a modification of the holding part ofFIG. 7;

FIG. 12 is a plan view of the separated type holding part and the malemember of FIG. 8;

FIG. 13 is a plan view of the integrated type holding part and the malemember;

FIG. 14 is a side view of the holding parts of FIGS. 7 and 8 seen fromthe buccal side;

FIG. 15 is a side sectional view, in a partial section, showing amounted state of the dental prosthesis according to the presentinvention;

FIG. 16 is a front view, in a partial section, showing an angle of themale member of the dental prosthesis according to the present invention;

FIG. 17 is a sectional view showing a state where the male member of theholding part is coupled to an artificial tooth of the dental prosthesisaccording to the present invention;

FIG. 18 is a side view showing a mounted state of the prosthesisaccording to the present invention;

FIG. 19 is a perspective view of an embedded type holding part accordingto the present invention;

FIG. 20 is a perspective view of the embedded type holding partaccording to the present invention;

FIG. 21 is a perspective view of the embedded type holding partaccording to the present invention;

FIG. 22 is a perspective view of the embedded type holding partaccording to the present invention;

FIG. 23 is a perspective view showing a state where an embedded part isadded to FIG. 19;

FIG. 24 is a perspective view showing a modification of the holding partof FIG. 19;

FIG. 25 is a front view and a perspective view showing an indentedportion of a scratch type;

FIG. 26 is a front view and a perspective view showing an indentedportion of a dot type;

FIG. 27 is a front view and a perspective view showing an indentedportion of a hole type;

FIG. 28 is a front view and a perspective view showing an indentedportion of a box type;

FIG. 29 is a front view showing a grinding portion on a lingual side ofthe anterior tooth;

FIG. 30 is a front view showing another grinding portion on the lingualside of the anterior tooth;

FIG. 31 is a perspective view showing the embedment at the rear of anembedded type holding part;

FIG. 32 is a perspective view showing another embedment at the rear ofthe embedded type holding part;

FIG. 33 is a plan view of the embedded type holding part and a malemember;

FIG. 34 is a side view of the holding parts seen from the buccal side;

FIG. 35 is a side sectional view, in a partial section, showing amounted state of the dental prosthesis according to the presentinvention;

FIG. 36 is a front view, in a partial section, showing an angle of themale member of the dental prosthesis according to the present invention;and

FIG. 37 is a sectional view showing a state where the male member of theholding part is coupled to an artificial tooth of the dental prosthesisaccording to the present invention

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIGS. 3 to 17 are views showing a dental prosthesis according to apreferred embodiment of the present invention.

As shown in FIGS. 3 and 4, the dental prosthesis according to thepresent invention includes: an artificial tooth 5 having female members6 and slots 6 a; and holding parts 3 and 4 respectively having malemembers 7 formed integrally with the holding parts 3 and 4 and insertedinto the female members 6 and the slots 6 a of the artificial tooth 5,and fixed to an adjacent tooth 8.

Combining force between the holding parts 3 and 4 and the adjacent tooth8 is increased by maximizing an area of the holding parts 3 and 4, andcombining force between the holding parts 3 and 4 and the artificialtooth 5 is increased by maximizing an area of the female member 6 andthe male member 7. At this time, sizes of the female member 6 and themale member 7 are adjustable according to circumstances.

Meanwhile, the male member 7 and the holding parts 3 and 4 are formedintegrally with each other as shown in FIG. 7, or divided into a lingualside and a buccal side as shown in FIG. 8.

Furthermore, in the case where the male member 7 and the holding parts 3and 4 are divided into the lingual side and the buccal side and there isno tooth at the back of the holding parts 3 and 4, as shown in FIG. 9, apair of projection 9 a and groove 9 b are formed at the ends of thelingual holding part 3 and the buccal holding part 4 and coupled witheach other in order to increase combining force between the holdingparts 3 and 4.

After that, in case of the adjacent tooth 8 whose holding parts 3 and 4may be exposed to the outside, as shown in FIGS. 12 and 13(3), on theanterior tooth and a portion which requires an aesthetic sense, only thelingual holding part 3 is formed, but on the posterior tooth as shown inFIG. 4, the lingual holding part 3 and the buccal holding part 4 may beformed separately as shown in FIG. 8 or integrally as shown in FIG. 7.Alternatively, the prosthesis can be formed in an S shape (FIG. 6) insuch a way that only the lingual holding part 3 is mounted on theanterior tooth and the front portion of the artificial tooth and onlythe buccal holding part 4 is mounted on a molar tooth and the posteriortooth of the artificial tooth. In the prosthesis having the abovestructure, the holding part is not exposed to the outside since only thelingual holding part 3 is mounted on the anterior tooth and the portion,which requires the aesthetic sense.

Meanwhile, as shown in FIG. 10, the holding parts 3 and 4 aremanufactured in such a way that the pit, the non-functional cusp and theentire or a part of the occlusal surface, which is not in contact withthe opposite tooth, are covered. Furthermore, the lingual holding part 3mounted on the anterior tooth and the portion which requires theaesthetic sense covers the lingual side to the maximum within a rangenot causing any obstacle to occlusion, whereby the prosthesis can endurelateral pressure and vertical pressure.

Moreover, the male member 7 may be formed in one of T, I, L and O shapesand other various shapes in order to maximize holding force between thefemale member 6 and the male member 7. Shape of the female member 6 andthe slot 6 a is determined according to the shape of the male member 7.

Additionally, as shown in FIG. 5, in the case where there is any missingtooth at the right or left of the adjacent tooth, since the prosthesiscan be manufactured in such a way that the male member 7 is formed atthe right or left of the holding part, it can prosthetically treat themissing tooth in any cases with no grinding.

The male member 7 having the above structure serves to keep parallelbetween the missing adjacent teeth together with the holding part, so asto lead a smooth insertion of the artificial tooth 5 and reinforcecompression resistance.

Therefore, the prosthesis according to the present invention can endurevertical pressure and horizontal pressure using elasticity of metal ofthe prosthesis used for tooth restoration, and the structure andgradient of the tooth to the maximum, and endure any external forces bysurrounding the lingual pit and the buccal pit, the non-functional cusp,and the occlusal surface of the adjacent tooth, which are not in contactwith the opposite tooth during occlusion.

Meanwhile, a method for manufacturing the dental prosthesis according tothe present invention includes the steps of: duplicating an originalmodel; waxing up the duplicated model; holding a sprue on the duplicatedmodel in a state where the duplicated model is waxed up, and investing,burning out and casting the duplicated model.

In the case of the holding part and the female member manufactured bythe above method, even though there is an under-cut, the lingual holdingpart can be formed from the lingual part at least to an area where thebuccal part is started and the buccal holding part can be formed fromthe buccal part at least to an area where the lingual part is started.In the present invention, not only the separate type holding parts butalso the integrated type holding parts can be attached to the lingualand buccal pits, the non-functional cusp and the occlusal surface, whichis not in contact with the opposite tooth, of the missing adjacent toothwith no grinding of the tooth.

As shown in FIG. 11, the holding part has a groove 10 formed at the rearthereof in order to increase flexibility of the holding part, to coverthe lingual and buccal pits, the non-functional cusp and the occlusalsurface, which is not in contact with the opposite tooth, to themaximum, and to be easily mounted the holding part

As described above, the lingual holding part 3 and the buccal holdingpart 4 can be formed integrally with each other.

MODE FOR THE INVENTION

Hereinafter, referring to FIGS. 18 to 37, the integrated type holdingpart 1 will be described in detail.

The dental prosthesis according to the present invention includes theholding part 1, a projection 9 formed on the holding part 1, a malemember 7 attached on the holding part 1, and a female member 6 formed onan artificial tooth 5.

The holding part 1 may have one of various forms in consideration ofholding force and an aesthetic sense, for example, a form that theholding part 1 is restricted only to a ground adjacent side (FIG. 22), aform that the holding part 1 extends from the ground adjacent side tothe lingual side (FIG. 20), a form that the holding part 1 extends fromthe ground adjacent side to the buccal side (FIG. 21), or a form thatthe holding part 1 extends to the lingual side and the buccal side (FIG.19). The ground form and size of the holding part 1 can be changedaccording to the size and position of the adjacent side of the lostadjacent tooth 8. Grinding is carried out within a range that a patientdoes not feel or sense abnormality without anesthesia. At this time, theholding part 1 has a depth of 0.5 mm˜2 mm. Grinding of the embedded typeholding part 1 of the anterior tooth or a portion requiring theaesthetic sense is carried out at the lingual side and the adjacent side(including or not including the occlusal surface, but grinding of theholding part 1 of the premolar and the molar is restricted only to theadjacent side (including or not including the occlusal surface of theadjacent side), carried out only at the adjacent side and the lingualside (including or not including the occlusal surface of the lingualside) or the buccal side (including or not including the occlusalsurface of the buccal side), or carried out at the adjacent side and thelingual and buccal sides (including or not including the occlusalsurfaces of the lingual and buccal sides). The holding part 1 may have aprojection 91 formed on a lingual or buccal end portion thereof. At thistime, the adjacent tooth has an indented portion 26, which adopts anyone of a hole type 23, a scratch type 21, a dot type 22, a rectangletype 24, a pin hole type, and other types according to the shape of theprojection 91 of the holding part 1.

The ground portion has a predetermined angle in order to increaseholding force of the holding part 1. The coverage of the holding part 1is changed according to holding force of a necessary amount (FIG. 24).Alternatively, the projection 91 is formed on the lingual or buccal endportion of the holding part in a state where the adjacent side of theholding part is not ground (FIGS. 31 and 32), or formed on the adjacenttooth 8 where the adjacent side is ground and the lingual and buccalsides are ended in order to maximize holding force between the lingualand buccal holding parts and the adjacent tooth (FIGS. 31 and 32). Toobtain a wide holding part including the ground surface and the adjacentground portion which require much holding force, the original model isduplicated, the duplicated model is waxed up, and a sprue is held on theduplicated model without removing the waxed-up model from the duplicatedmodel. After that, the duplicated model is invested, burned out andcast, and then mounted) to the original model. At this time, thecoverage of the ground surface, the adjacent portion, the lingual sideand the buccal side is adjustable according to the form and position ofthe tooth. An area where much holding force is not needed, namely, anarea where there are no ground portion and undercut, is waxed up on theoriginal model. After that, the sprue is held on the waxed-up model, andthe waxed-up model is invested, burned out and cast, and then, seamed tothe original model. Therefore, in the above case, the duplicated modelis not needed. On an area where little holding force is required, thedental prosthesis can be manufactured in such a way that the holdingpart is applied only to the ground portion. On an area where anaesthetic sense is required, the holding part is positioned from theground adjacent side only to the lingual side (FIG. 20) or only at theadjacent side (FIG. 22).

On an area where does not attach importance to the aesthetic sense, theholding part 1 extends to the lingual and buccal sides (FIG. 19).Moreover, the holding part 1 may cover the non-functional cusp and aportion of the occlusal surface where there is no obstacle in occlusionin order to obtain holding force to the maximum (FIG. 24). The malemember 7 attached on the holding part 1 may take one of I, L, O and Tforms and other modified forms in order to obtain the maximum couplingforce between the male member 7 and the female member 6. Additionally,The male member 7 attached on the holding part 1 promotes a smoothinsertion of the artificial tooth 5 by keeping parallel with the lostadjacent abutment and permits the dental prosthesis to endure occlusalforce and lateral force by reinforcing compression resistance. Thedental prosthesis according to the present invention does not causedegeneration of the dental pulp, exposure of the dental pulp, change ofthe opposite tooth, and hypersensitivity since it conserves the occlusalsurface as it is with little grinding amount of the tooth when the losttooth is restored.

The artificial tooth 5 may be made of ceramic or metal material. By theabove method, the lost tooth can be restored with low cost within ashort operation time period, differently from the prior art crown bridgeprosthesis.

1. A dental prosthesis, which includes holding parts for fixing anadjacent tooth a male member formed integrally with the holding parts, afemale member formed integrally with an artificial tooth and having aslot to insert the male member thereto to thereby recover or promote afunction of a damaged tooth, wherein the holding parts cover a part orthe whole of the adjacent tooth to surround the adjacent tooth theholding parts are modeled on the original surface pattern of theadjacent tooth to provide the same surface pattern as the adjacent toothwhereby the holding parts can be fixed to the adjacent tooth with no orlittle grinding of the adjacent tooth.
 2. The dental prosthesisaccording to claim 1, wherein the male member is formed at both ends oronly one end of the holding part.
 3. The dental prosthesis according toclaim 1, wherein the male member and the holding parts have a lingualside and a buccal side formed integrally.
 4. The dental prosthesisaccording to claim 1, wherein the male member and the holding part areformed separately at the lingual side and the buccal side
 4. 5. Thedental prosthesis according to claim 1, wherein the holding part isformed only at the lingual side.
 6. The dental prosthesis according toclaim 1, wherein the dental prosthesis is S-shaped in such a way that onthe anterior tooth and the front part of the artificial tooth, only thelingual holding part is located, and on the molar and the rear part ofthe artificial tooth, only the buccal holding part is located.
 7. Thedental prosthesis according to claim 1, wherein the holding part has arecess formed at the rear portion thereof in order to cover the lingualand buccal pits, non-functional cusp and a portion, which is not incontact with the opposite tooth, to the maximum, easily mount theholding part, and increase flexibility of the holding part. 8.(canceled)
 9. (canceled)
 10. The dental prosthesis according to claim 4,wherein the separate type holding part having the lingual holding partand the buccal holding part includes a pair of projection and grooveformed at ends thereof and coupled with each other.
 11. The dentalprosthesis according to claim 1, wherein the holding part can cover thepit, non-functional cusp and a part or the whole of the occlusal surfacewith which the opposite tooth is not in contact.
 12. A method formanufacturing a dental prosthesis comprising the steps of: duplicatingan original model; waxing up the duplicated model; holding a sprue onthe duplicated model in a state where the duplicated model is waxed up;and investing, burning out and casting the duplicated model.
 13. Thedental prosthesis according to claim 1, wherein an embedded type holdingpart is formed in such a way as to form a projection to the holding partand an indented portion corresponding to the projection is formed on theadjacent face of the adjacent tooth to thereby strengthen holding forceof the holding part.
 14. The dental prosthesis according to claim 13,wherein the embedded typeholding part is to increase holding force, andis mounted only on a ground adjacent side of the adjacent tooth, withina range from the ground adjacent side to the lingual side of theadjacent tooth, within a range from the ground adjacent side to thebuccal side of the adjacent tooth, within a range from the groundadjacent side to the lingual side and the buccal side, or on the buccalside or the lingual side after grinding.
 15. The dental prosthesisaccording to claim 13, wherein the embedded type holding part hasprojection formed in the rear portion thereof to secure holding force,and can increase the holding force only with the projection of theadjacent tooth even in a state where the adjacent side of the holdingpart is not ground.
 16. The dental prosthesis according to claim 13,wherein the embedded type holding part additionally extends from theadjacent side, the buccal side and the lingual side to an occlusalsurface of the adjacent tooth.
 17. The dental prosthesis according toclaim 2, wherein the holding part can cover the pit, non-functional cuspand a part or the whole of the occlusal surface with which the oppositetooth is not in contact.
 18. The dental prosthesis according to claim 3,wherein the holding part can cover the pit, non-functional cusp and apart or the whole of the occlusal surface with which the opposite toothis not in contact.
 19. The dental prosthesis according to claim 4,wherein the holding part can cover the pit, non-functional cusp and apart or the whole of the occlusal surface with which the opposite toothis not in contact.
 20. The dental prosthesis according to claim 5,wherein the holding part can cover the pit, non-functional cusp and apart or the whole of the occlusal surface with which the opposite toothis not in contact.
 21. The dental prosthesis according to claim 6,wherein the holding part can cover the pit, non-functional cusp and apart or the whole of the occlusal surface with which the opposite toothis not in contact.
 22. The dental prosthesis according to claim 7,wherein the holding part can cover the pit, non-functional cusp and apart or the whole of the occlusal surface with which the opposite toothis not in contact.
 23. The dental prosthesis according to claim 10,wherein the holding part can cover the pit, non-functional cusp and apart or the whole of the occlusal surface with which the opposite toothis not in contact.